Returns Sorry when it should have returned Yes

def shut_down(s):    
if s == "yes":
    return shut_down("Shutting down")
elif s == "no":
 return shut_down("Shutdown aborted")
    return "Sorry"



When s === 'yes', the return value is a recursive call to the same function, this time with the argument, "Shutting down", which is not "yes", hence, "Sorry".

The thing to do would be to return (or print) "Shutting down".